Verify that user name when logging in is an Email address

Sorry, please locate the foreach loop below and add a case for email and it should works now :

switch( $field_settings["type"] ){
        case "select":
            foreach( $options as &$o ){
                $fieldStr .= "{$o}";
            }
            $fieldStr = "{$fieldStr}";
        break;
        case "radio":
            foreach( $options as $k=>&$o ){
                $fieldStr .= "{$o}";
            }
        break;
        case "checkbox":
        case "text":
        case "password":
            $fieldStr = "";
        break;
        case "email":
            $fieldStr = "";
        break;
    }